V65 Engine Breather

Technical Small Block V Twins (not new V7s)
1

I’d like to simplify the engine breather arrangements on my V65.

I removed the big air filter box a couple of years ago and fitted K&N;s to the carbs. The upper most breather pipe now just vents under the seat.

I’ve read all sorts of contrary advice on the internet about changing the engine breather - one even suggested you could not have an oil return to the sump. I like that idea but not sure it would cause any problems. Considering the amount of sludge that builds up in that oil pipe I’m not convinced it would drain into the sump anyway?

Anyone done anything clever with theirs???

ta
stuart

2

In this article there are dire warnings about not having the return feed to the sump. I’ve followed this advice,better safe than sorry.

http://www.thisoldtractor.com/moto_guzzi_small_blocks_older_small_block_issues_.html

3

have always removed the sump return from the breather system on every guzzi i have owned.


try catching a months worth of breather mayo and water in a bottle, scary how much comes out and what it does to your nice clean oil

Just check your oil level regularly!

4

Excellent ! I’m glad you said that.

I had the opportunity to strip down a V50 engine recently. The sump return pipe is just a straight tube (no non-return valve) and the sump return was also just a threaded hole. The breather system can’t be sealed (as claimed by some) else you couldn’t pull any air through the air filter into the carbs.
Likewise, I find the return to sump pipe fills with emulsion which I don’t particularly want mixing with the engine oil. I already check the engine oil level before riding the bike so this will be an interesting (?) experiment.

Thanks again, stuart.

5

did 2500 miles last year on my v35 monza (long story…) and i have my sump return connection sealed with a suitable bolt and crush washer. Â Only breathers I have are the 2 rocker box outlets connected to a T piece and then off to the rear seat mount. Â Gets scary amount of majo out over the mud guard even in summer.

My old t5 did 40,000 miles with same setup

6

have k&ns fitted to my &50 Strada. Breather pipes are joined by a T and fed out to open air behind rear wheel. no bothers in the last 3 years

7

‘Mayo’ is an unavoidable consequence of condensation in the engine, and the best way to keep it down (not sure it can ever be completely eradicated ~ and by the way you can get it in car engines too) is to get the engine and its oil hot enough to boil out the water. I.e. frequent short journeys in cold weather are the worst. Not sure you should be blocking pipes and so on to try to stop mayo forming in various whatever places, as A. I think you’re just flogging a dead horse; B. it’s interfering with a crankcase breather system which most likely works perfectly well as it was designed. Just IMHO.

8

the breather system is intack, its just the mayo return pipe blocked, the oem breather is a disaster on the small block guzzi’s.

makes no odds imho what you do as long as the block does not pressurise and you don’t let and oil on to the road.


Far as my bike does the less mayo getting back into the engine the better. Due to heath issues the furthest my bike regulary goes is about 20 Miles. Â Clocks back and forward are the only longer runs at about 30 miles so mayo is a constant issue.

This is my 5th guzzi and every one including the spine breather’ed  T5 have all had  breather systems that were flawed from the factory but  easily sorted!

next project is to fit a remote gearbox breather and we will then have a totally leak free guzzi